/**
 * A concrete state for generating bill
 */

import java.io.*;

public class GenerateBill extends ShopState {
    public static boolean instanceFlag = false; //true if have 1 instance

    private GenerateBill() {
    }

    public static GenerateBill getInstance() {
        if (!instanceFlag) {
            instanceFlag = true;
            return new GenerateBill();
        }
        return null;
    }

    public void generateBill() {
        System.out.println("The state is generating bill now !");
    }
}
